aboutsummaryrefslogtreecommitdiff
path: root/net/wireless/core.c
blob: 0668b2bfc1dafb4c880b565a1a12ec8e30e9e329 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
/*
 * This is the linux wireless configuration interface.
 *
 * Copyright 2006-2008		Johannes Berg <johannes@sipsolutions.net>
 */

#include <linux/if.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/nl80211.h>
#include <linux/debugfs.h>
#include <linux/notifier.h>
#include <linux/device.h>
#include <net/genetlink.h>
#include <net/cfg80211.h>
#include <net/wireless.h>
#include "nl80211.h"
#include "core.h"
#include "sysfs.h"

/* name for sysfs, %d is appended */
#define PHY_NAME "phy"

MODULE_AUTHOR("Johannes Berg");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("wireless configuration support");

/* RCU might be appropriate here since we usually
 * only read the list, and that can happen quite
 * often because we need to do it for each command */
LIST_HEAD(cfg80211_drv_list);
DEFINE_MUTEX(cfg80211_drv_mutex);

/* for debugfs */
static struct dentry *ieee80211_debugfs_dir;

/* requires cfg80211_drv_mutex to be held! */
static struct cfg80211_registered_device *cfg80211_drv_by_wiphy(int wiphy)
{
	struct cfg80211_registered_device *result = NULL, *drv;

	list_for_each_entry(drv, &cfg80211_drv_list, list) {
		if (drv->idx == wiphy) {
			result = drv;
			break;
		}
	}

	return result;
}

/* requires cfg80211_drv_mutex to be held! */
static struct cfg80211_registered_device *
__cfg80211_drv_from_info(struct genl_info *info)
{
	int ifindex;
	struct cfg80211_registered_device *bywiphy = NULL, *byifidx = NULL;
	struct net_device *dev;
	int err = -EINVAL;

	if (info->attrs[NL80211_ATTR_WIPHY]) {
		bywiphy = cfg80211_drv_by_wiphy(
				nla_get_u32(info->attrs[NL80211_ATTR_WIPHY]));
		err = -ENODEV;
	}

	if (info->attrs[NL80211_ATTR_IFINDEX]) {
		ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
		dev = dev_get_by_index(&init_net, ifindex);
		if (dev) {
			if (dev->ieee80211_ptr)
				byifidx =
					wiphy_to_dev(dev->ieee80211_ptr->wiphy);
			dev_put(dev);
		}
		err = -ENODEV;
	}

	if (bywiphy && byifidx) {
		if (bywiphy != byifidx)
			return ERR_PTR(-EINVAL);
		else
			return bywiphy; /* == byifidx */
	}
	if (bywiphy)
		return bywiphy;

	if (byifidx)
		return byifidx;

	return ERR_PTR(err);
}

struct cfg80211_registered_device *
cfg80211_get_dev_from_info(struct genl_info *info)
{
	struct cfg80211_registered_device *drv;

	mutex_lock(&cfg80211_drv_mutex);
	drv = __cfg80211_drv_from_info(info);

	/* if it is not an error we grab the lock on
	 * it to assure it won't be going away while
	 * we operate on it */
	if (!IS_ERR(drv))
		mutex_lock(&drv->mtx);

	mutex_unlock(&cfg80211_drv_mutex);

	return drv;
}

struct cfg80211_registered_device *
cfg80211_get_dev_from_ifindex(int ifindex)
{
	struct cfg80211_registered_device *drv = ERR_PTR(-ENODEV);
	struct net_device *dev;

	mutex_lock(&cfg80211_drv_mutex);
	dev = dev_get_by_index(&init_net, ifindex);
	if (!dev)
		goto out;
	if (dev->ieee80211_ptr) {
		drv = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
		mutex_lock(&drv->mtx);
	} else
		drv = ERR_PTR(-ENODEV);
	dev_put(dev);
 out:
	mutex_unlock(&cfg80211_drv_mutex);
	return drv;
}

void cfg80211_put_dev(struct cfg80211_registered_device *drv)
{
	BUG_ON(IS_ERR(drv));
	mutex_unlock(&drv->mtx);
}

int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
			char *newname)
{
	struct cfg80211_registered_device *drv;
	int idx, taken = -1, result, digits;

	mutex_lock(&cfg80211_drv_mutex);

	/* prohibit calling the thing phy%d when %d is not its number */
	sscanf(newname, PHY_NAME "%d%n", &idx, &taken);
	if (taken == strlen(newname) && idx != rdev->idx) {
		/* count number of places needed to print idx */
		digits = 1;
		while (idx /= 10)
			digits++;
		/*
		 * deny the name if it is phy<idx> where <idx> is printed
		 * without leading zeroes. taken == strlen(newname) here
		 */
		result = -EINVAL;
		if (taken == strlen(PHY_NAME) + digits)
			goto out_unlock;
	}


	/* Ignore nop renames */
	result = 0;
	if (strcmp(newname, dev_name(&rdev->wiphy.dev)) == 0)
		goto out_unlock;

	/* Ensure another device does not already have this name. */
	list_for_each_entry(drv, &cfg80211_drv_list, list) {
		result = -EINVAL;
		if (strcmp(newname, dev_name(&drv->wiphy.dev)) == 0)
			goto out_unlock;
	}

	/* this will only check for collisions in sysfs
	 * which is not even always compiled in.
	 */
	result = device_rename(&rdev->wiphy.dev, newname);
	if (result)
		goto out_unlock;

	if (rdev->wiphy.debugfsdir &&
	    !debugfs_rename(rdev->wiphy.debugfsdir->d_parent,
			    rdev->wiphy.debugfsdir,
			    rdev->wiphy.debugfsdir->d_parent,
			    newname))
		printk(KERN_ERR "cfg80211: failed to rename debugfs dir to %s!\n",
		       newname);

	result = 0;
out_unlock:
	mutex_unlock(&cfg80211_drv_mutex);
	if (result == 0)
		nl80211_notify_dev_rename(rdev);

	return result;
}

/* exported functions */

struct wiphy *wiphy_new(struct cfg80211_ops *ops, int sizeof_priv)
{
	static int wiphy_counter;

	struct cfg80211_registered_device *drv;
	int alloc_size;

	WARN_ON(!ops->add_key && ops->del_key);
	WARN_ON(ops->add_key && !ops->del_key);

	alloc_size = sizeof(*drv) + sizeof_priv;

	drv = kzalloc(alloc_size, GFP_KERNEL);
	if (!drv)
		return NULL;

	drv->ops = ops;

	mutex_lock(&cfg80211_drv_mutex);

	drv->idx = wiphy_counter++;

	if (unlikely(drv->idx < 0)) {
		wiphy_counter--;
		mutex_unlock(&cfg80211_drv_mutex);
		/* ugh, wrapped! */
		kfree(drv);
		return NULL;
	}

	mutex_unlock(&cfg80211_drv_mutex);

	/* give it a proper name */
	dev_set_name(&drv->wiphy.dev, PHY_NAME "%d", drv->idx);

	mutex_init(&drv->mtx);
	mutex_init(&drv->devlist_mtx);
	INIT_LIST_HEAD(&drv->netdev_list);
	spin_lock_init(&drv->bss_lock);
	INIT_LIST_HEAD(&drv->bss_list);

	device_initialize(&drv->wiphy.dev);
	drv->wiphy.dev.class = &ieee80211_class;
	drv->wiphy.dev.platform_data = drv;

	return &drv->wiphy;
}
EXPORT_SYMBOL(wiphy_new);

int wiphy_register(struct wiphy *wiphy)
{
	struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
	int res;
	enum ieee80211_band band;
	struct ieee80211_supported_band *sband;
	bool have_band = false;
	int i;
	u16 ifmodes = wiphy->interface_modes;

	if (WARN_ON(wiphy->max_scan_ssids < 1))
		return -EINVAL;

	/* sanity check ifmodes */
	WARN_ON(!ifmodes);
	ifmodes &= ((1 << __NL80211_IFTYPE_AFTER_LAST) - 1) & ~1;
	if (WARN_ON(ifmodes != wiphy->interface_modes))
		wiphy->interface_modes = ifmodes;

	/* sanity check supported bands/channels */
	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
		sband = wiphy->bands[band];
		if (!sband)
			continue;

		sband->band = band;

		if (WARN_ON(!sband->n_channels || !sband->n_bitrates))
			return -EINVAL;

		/*
		 * Since we use a u32 for rate bitmaps in
		 * ieee80211_get_response_rate, we cannot
		 * have more than 32 legacy rates.
		 */
		if (WARN_ON(sband->n_bitrates > 32))
			return -EINVAL;

		for (i = 0; i < sband->n_channels; i++) {
			sband->channels[i].orig_flags =
				sband->channels[i].flags;
			sband->channels[i].orig_mag =
				sband->channels[i].max_antenna_gain;
			sband->channels[i].orig_mpwr =
				sband->channels[i].max_power;
			sband->channels[i].band = band;
		}

		have_band = true;
	}

	if (!have_band) {
		WARN_ON(1);
		return -EINVAL;
	}

	/* check and set up bitrates */
	ieee80211_set_bitrate_flags(wiphy);

	mutex_lock(&cfg80211_drv_mutex);

	/* set up regulatory info */
	wiphy_update_regulatory(wiphy, REGDOM_SET_BY_CORE);

	res = device_add(&drv->wiphy.dev);
	if (res)
		goto out_unlock;

	list_add(&drv->list, &cfg80211_drv_list);

	/* add to debugfs */
	drv->wiphy.debugfsdir =
		debugfs_create_dir(wiphy_name(&drv->wiphy),
				   ieee80211_debugfs_dir);
	if (IS_ERR(drv->wiphy.debugfsdir))
		drv->wiphy.debugfsdir = NULL;

	res = 0;
out_unlock:
	mutex_unlock(&cfg80211_drv_mutex);
	return res;
}
EXPORT_SYMBOL(wiphy_register);

void wiphy_unregister(struct wiphy *wiphy)
{
	struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);

	/* protect the device list */
	mutex_lock(&cfg80211_drv_mutex);

	BUG_ON(!list_empty(&drv->netdev_list));

	/*
	 * Try to grab drv->mtx. If a command is still in progress,
	 * hopefully the driver will refuse it since it's tearing
	 * down the device already. We wait for this command to complete
	 * before unlinking the item from the list.
	 * Note: as codified by the BUG_ON above we cannot get here if
	 * a virtual interface is still associated. Hence, we can only
	 * get to lock contention here if userspace issues a command
	 * that identified the hardware by wiphy index.
	 */
	mutex_lock(&drv->mtx);
	/* unlock again before freeing */
	mutex_unlock(&drv->mtx);

	/* If this device got a regulatory hint tell core its
	 * free to listen now to a new shiny device regulatory hint */
	reg_device_remove(wiphy);

	list_del(&drv->list);
	device_del(&drv->wiphy.dev);
	debugfs_remove(drv->wiphy.debugfsdir);

	mutex_unlock(&cfg80211_drv_mutex);
}
EXPORT_SYMBOL(wiphy_unregister);

void cfg80211_dev_free(struct cfg80211_registered_device *drv)
{
	struct cfg80211_internal_bss *scan, *tmp;
	mutex_destroy(&drv->mtx);
	mutex_destroy(&drv->devlist_mtx);
	list_for_each_entry_safe(scan, tmp, &drv->bss_list, list)
		cfg80211_put_bss(&scan->pub);
	kfree(drv);
}

void wiphy_free(struct wiphy *wiphy)
{
	put_device(&wiphy->dev);
}
EXPORT_SYMBOL(wiphy_free);

static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
					 unsigned long state,
					 void *ndev)
{
	struct net_device *dev = ndev;
	struct cfg80211_registered_device *rdev;

	if (!dev->ieee80211_ptr)
		return 0;

	rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);

	WARN_ON(dev->ieee80211_ptr->iftype == NL80211_IFTYPE_UNSPECIFIED);

	switch (state) {
	case NETDEV_REGISTER:
		mutex_lock(&rdev->devlist_mtx);
		list_add(&dev->ieee80211_ptr->list, &rdev->netdev_list);
		if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
				      "phy80211")) {
			printk(KERN_ERR "wireless: failed to add phy80211 "
				"symlink to netdev!\n");
		}
		dev->ieee80211_ptr->netdev = dev;
		mutex_unlock(&rdev->devlist_mtx);
		break;
	case NETDEV_UNREGISTER:
		mutex_lock(&rdev->devlist_mtx);
		if (!list_empty(&dev->ieee80211_ptr->list)) {
			sysfs_remove_link(&dev->dev.kobj, "phy80211");
			list_del_init(&dev->ieee80211_ptr->list);
		}
		mutex_unlock(&rdev->devlist_mtx);
		break;
	}

	return 0;
}

static struct notifier_block cfg80211_netdev_notifier = {
	.notifier_call = cfg80211_netdev_notifier_call,
};

static int cfg80211_init(void)
{
	int err;

	err = wiphy_sysfs_init();
	if (err)
		goto out_fail_sysfs;

	err = register_netdevice_notifier(&cfg80211_netdev_notifier);
	if (err)
		goto out_fail_notifier;

	err = nl80211_init();
	if (err)
		goto out_fail_nl80211;

	ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);

	err = regulatory_init();
	if (err)
		goto out_fail_reg;

	return 0;

out_fail_reg:
	debugfs_remove(ieee80211_debugfs_dir);
out_fail_nl80211:
	unregister_netdevice_notifier(&cfg80211_netdev_notifier);
out_fail_notifier:
	wiphy_sysfs_exit();
out_fail_sysfs:
	return err;
}

subsys_initcall(cfg80211_init);

static void cfg80211_exit(void)
{
	debugfs_remove(ieee80211_debugfs_dir);
	nl80211_exit();
	unregister_netdevice_notifier(&cfg80211_netdev_notifier);
	wiphy_sysfs_exit();
	regulatory_exit();
}
module_exit(cfg80211_exit);